“Helping someone in desperate need is an ethical choice, yet it is a choice we would all make without hesitating, i.e. thinking a single thought. The reason, according to Harvard Law Professor Glenn Cohen, is that ethical choices start in the gut. Our intuition, programmed my millions of years of evolution, instructs us what to do without needing rational deliberation. But at times, especially when making an ethical decision implies a sacrifice on our behalf, rational deliberation is necessary, and likely inescapable.”
http://bigthink.com/videos/glenn-cohen-on-ethics-101-and-being-our-best-selves